Support is requested for the Sixth Banff Conference on Solid Organ Allograft Pathology, to be held April 21-28, 2001. This conference is the sixth in a series that has been held biennially, beginning in 1991. The Overall objectives of the Banff conferences are: to provide a venue for focus on the pathology and pathophysiology of solid organ allografts; to foster collaborative studies in the areas of allograft pathology and pathophysiology; and to enable broad representation and collaborations, interdisciplinary interactions, and consensus building. The conference in 1991 led to development of the Banff Working Formulation for classification of renal allograft pathology. In 1995, the Banff working formulation for liver allograft rejection was developed from consensus discussions held at the Third Banff conference. The conference in 1997 led to a revision of the Banff classification for kidney allograft pathology, published in 1999. The most recent conference in 1999 led to development to development of a schema for chronic changes in liver allografts. Attendance at the conferences grew steadily, from 16 in 1991 to 123 in 1999. The conferences are attended by an international group of pathologists and clinicians, most with strong research interests in transplantation. Formats are a mix of oral and poster presentations and open informal consensus discussions, which have proven to be productive forums for exchange of ideas and development of collaborations. The conferences provide a stimulating environment for young professionals interested in the science and practice of transplantation, and junior faculty have attended the conference in increasing numbers in recent years. The specific goals of the Sixth Banff conference are: 1) to update Banff Classifications for kidney and liver allografts, and classifications for acute rejection of heart, lung, and pancreas allografts, with special focus on heart allografts; 2) to develop a consensus approach to the use of sum scoring using Banff semiquantitative scoring; 3) to develop a proposal for defining antibody-mediated rejection syndromes, and to foster continued studies of the role of antibody in acute and chronic rejection; 4) to address the broad topic of chronic allograft changes, developing consensus on features enabling identification of discrete sub-groups, e.g. chronic rejection, chronic toxicity, chronic viral infection, within the broad classification of chronic allograft changes, potentially leading to an update the Banff grading system for chronic kidney allograft changes; 5) to redefine criteria for donor organ utilization/selection in kidney and liver allografts, and develop a grading system for donor biopsy pathology; 6) to further refine the diagnosis of and summarize the pathogenic significance of viral infections in solid organ allografts; 7) to provide a forum for discussion of the use of molecular markers in tissue and body fluids for the diagnosis of rejection and prognosis for allograft outcome; and 8) to consider the current status of transplantation telepathology and vision for the future of this important modality. Funds from this grant would provide travel support, registration and housing for young investigators to come to the Banff conference to present their work and participate in the formal sessions and informal consensus discussions that characterize these conferences. The work of young investigators will be highlighted as platform presentations or in interactive poster sessions. The other support requested is for AV support for the meeting and for microscopes for the working sessions in the conference program.